It's Earth Hour this weekend. And no matter how you feel about its message, I think we can all agree that seeing cities blanketed in darkness is chilling. So for this week's Shooting Challenge, photograph the darkness of Earth Hour.

This weekend, we'll begin daylight savings time. Next week, we'll get another peek at the Apple Watch. Time is on the mind. And so for this week's Shooting Challenge, photograph this largely invisible phenomenon by photographing watches and clocks.

Bubbles are micro-thin orbs of liquid suspended around gas. That's nuts. And yet they're never more than a squirt of dish soap away. These 12 photos from this week's Shooting Challenge are a small reminder that the little things around us are pretty amazing.

You left a few awesome habits behind when you grew up: Wearing dinosaur costumes, attending sleepovers, and maybe most importantly, blowing bubbles. So for this week's Shooting Challenge, photograph bubbles.

Fire! We're drawn to it like moths to a flame. (Wait...does that metaphor still work when it references the allure of fire?) Regardless, for this week's Shooting Challenge, you photographed flames, and here are the results.

Love. Is there anything more important? No. Which is why, even though Valentine's Day may be over, you still have nothing more important to do then check out the 12 photos of love, submitted for this week's Shooting Challenge.

Valentine's Day is this weekend. And whether or not you believe in spending $5.95 on Hallmark greetings, hopefully, you still believe in love. So for this week's Shooting Challenge, that's what we're celebrating: Love.

Coffee. You owe that shit. Big time. It gets you out of bed, keeps you employed, and only stains your teeth moderately. So for this week's Shooting Challenge, we're photographing coffee—in beans, brewing, and cups.

It's Christmas time. And no matter your faith, you'll probably agree, it's the most delicious cookie time of the year. Here are cookies that you baked and photographed. And if you're so brave as to bake yourself, many have the recipe, too!

Praise consumerism. There's no better feeling than ripping open present and seeing what's inside. So for our Christmas Shooting Challenge, let us open gifts with you. Create GIFs, photographing a present at various stages of undress.